Tubular sieve



March 14, 1967 w. UHRIG 3,309,046

TUBULAR S IEVE Original Filed Jan. 11, 1963 FEG.3

INVENTOR. WILHELM UHRIG AGENT BY M m United States Patent Office 3,309,046 Patented Mar. 14, 1967 This application is a continuation of my copending application Ser. No. 250,888, filed on Jan. 11, 1963, now abandoned.

The present invention relates to improvements in tubular sieves of particular usefulness in paper-making machinery.

As is known in the paper-making art, the beaten and mixed pulp is poured on a very fine screen which is in the form of an endless belt several feet wide. Vibration of the screen or sieve spreads the material in a thin uniform layer. As it is carried along, much water in the soft mass drains out. To prevent the material from running over the edge, thick rubber belts or other suitable rim means are placed on either side. Mechanical suction removes much of the water left after draining, after which the felted mass passes from the sieve between rollers to the finishing paper-making stations.

Screens or sieves of this type must, of course, be flexible and resist the mechanical stresses exerted thereupon. They also should have openings of even size evenly distributed over their entire surface. In an effort to accomplish these objectives, it has been proposed to make such sieves of woven tubular fabrics Whose warp threads extend in the direction of the longitudinal axis of the tubular sieve while the weft or filling threads extended transversely thereto in helical windings from one sieve rim to the other sieve rim. However, special lOOms have been required for weaving such tubular fabrics.

It is one of the objects of the present invention to make the manufacture of tubular sieves more economical and to produce such sieves without using special looms.

It is another object of this invention to produce a better tubular sieve having a prolonged service life in papermaking machinery.

With these objects and others in view, this invention, in one of its more specific aspects, resides in a sieve for a papermakingmachine and the like in which two elongated rim members extend in substantially parallel, laterally spaced, closed loops which define a closed surface therebetween. At least one elongated, fiat, woven band extends in this surface in at least three laterally juxtaposed parallel turns, the end portions of the band or bands being fastened to the two rim members respectively, and the longitudinal edges of each turn being obliquely inclined relative to the loops of the rim members.

The edges of each turn are fastened to edges of respective adjacent turns, and the band is formed with mesh openings therethrough transversely of the aforementioned surface.

The end portions of the band or hands are cut obliquely relative to the direction of band elongation and parallel to the associated rim members and the cut ends are provided with a binding agent which may be an adhesive and also may fasten the cut ends to the rim members. Each band preferably extends over more than one turn.

The band material may consist partly or entirely of metallic filaments as is conventional in this art, and the several turns may be fastened to each other by sewn seams.

Other objects, advantages and features of the present invention will become more apparent in the following detailed description of certain now preferred embodiments thereof, taken in conjunction with the accompanying drawing wherein FIG. 1 shows a screen or sieve of the invention together with other elements of a papermaking machine in top plan view;

FIG. 2 illustrates the device of FIG. 1 in front elevation;

FIG. 3 shows a detail of the sieve of FIG. 1 in plan View on a larger scale; and

FIG. 4 shows the sieve of FIG. 1 in fragmentary sideelevational section on the line IVIV.

Referring initially to FIGS. 1 and 2 there is seen as much of a papermaking machine as is needed for an understanding of this invention. A continuous screen or sieve 10 is supported on two parallel rolls 11, 12 of which at least one is rotated about its axis by means not shown. The screen includes two rim members 13, 14 which form respective parallel closed loops about the rolls 11, 12 and are spaced in the direction of the roll axes. Several turns 15 of a woven bronze wire material are arranged between the rim members 13, 14.

Each turn 15 consists of a relatively narrow elongated portion of a continuous strip of the woven material. While only two turns 15 are visible in FIGS. 3 and 4, it will be understood that at least three turns are necessary as is shown in FIG. 1.

Reverting to FIG. 1, it is seen that the longitudinal edges of the woven strip which constitutes the turns 15 are cut obliquely relative to the direction of strip elongation and that the obliquely cut ends are fastened to the rim members 13, 14. As is best seen in FIG. 4, the rim members 13, 14 are U-shaped channels of resilient plastic. The obliquely cut ends of the woven material are impregnated with an adhesive binding agent, not visible in the drawing, which prevents unraveling of the cut threads and adhesively bonds the cut end to the associated rim member.

The longitudinal edges of each turn 15 which connect the obliquely cut ends are fastened to the edges of two contiguously adjacent turns 15 by sewn seams 16 constituted by metal threads 17 as is seen in more detail in FIGS. 3 and 4.

The interstices between the Warp threads 18 and filling threads 19 of the woven strip provide the mesh openings in the screen which retain pulp fibers but permit the passage of liquid through the screen.

While the invention has been described in connection with certain now preferred embodiments, it will be clearly understood that many variations and modifications may occur to those skilled in the art, particularly after benefiting from the present teaching, without departing from the spirit and scope of this invention as defined in the appended claims.

What is claimed is:

1. A sieve for papermaking machines and the like comprising, in combination:

(a) two elongated rim members extending in substantially parallel, laterally spaced, closed loops defining a closed surface therebetween; (b) an elongated, fiat, woven continuous band extending in said surface in at least three laterally juxtaposed parallel continuous turns, said band having two end portions respectively fastened to said rim members and said turns having longitudinal edges obliquely inclined relative to said loops; and (c) fastening means connecting the edges of each turn to a respective edge of an adjacent turn,

(1) the band being formed with mesh openings therethrough transversely of said surface.

2. A sieve as set forth in claim 1, wherein said end portions are cut obliquely relative to the direction of elongation of the band and parallel to the direction of elongation of the associated rim member.

3. A sieve as set forth in claim 1, further comprising a binding agent on the end portions of the woven band.

4.- A sieve as set forth in claim 3, wherein said binding agent is an adhesive connecting said end portions to the rim members.

5. A sieve asset forth in claim 1, wherein the woven band contains metallic, filaments.

6. A sieve as set'forth inclaim 1, wherein said fasten-1 ing means include a sewn seam.

4/1922 Hurrell 210-497.1 4/1927 Kurtz-Hahnle et al.

4 10/ 1938 Webb. 10/1944 McFarlane 210,-508 X 5/1952 Fessler 210-489 11/1952 Parsons et a1 210,-400 X 4/1956 Fogwell 210489 X 5/ 1962 Billner 210499 X 9/1962 Morrison 21040l' X 9/ 1962 Morrison 21049.9. X 7/1963 Spangler et a1 2l0-508 X FOREIGN PATENTS 5/ 1960 Austria. 7/ 1901 Germany. 4/ 1954 Great Britain. 11/1951 Italy, 10/ 1926 Switzerland.

REUBEN FRIEDMAN, Primary Examiner.

20 D. RIESS, Assistant Examiner. 

1. A SIEVE FOR PAPERMAKING MACHINES AND THE LIKE COMPRISING, IN COMBINATION: (A) TWO ELONGATED RIM MEMBERS EXTENDING IN SUBSTANTIALLY PARALLEL, LATERALLY SPACED, CLOSED LOOPS DEFINING A CLOSED SURFACE THEREBETWEEN; (B) AN ELONGATED, FLAT, WOVEN CONTINUOUS BAND EXTENDING IN SAID SURFACE IN AT LEAST THREE LATERALLY JUXTAPOSED PARALLEL CONTINUOUS TURNS, SAID BAND HAVING TWO END PORTIONS RESPECTIVELY FASTENED TO SAID RIM MEMBERS AND SAID TURNS HAVING LONGITUDINAL EDGES OBLIQUELY INCLINED RELATIVE TO SAID LOOPS; AND (C) FASTENING MEANS CONNECTING THE EDGES OF EACH TURN TO A RESPECTIVE EDGE OF AN ADJACENT TURN, (1) THE BAND BEING FORMED WITH MESH OPENINGS THERETHROUGH TRANSVERSELY OF SAID SURFACE. 